title: Survival of infectious prions in Class B biosolids.
abstract: This study developed a method for extracting infectious prions from Class B biosolids and subsequently evaluated the survival of infectious prions under the influence of mesophilic (37°C) and thermophilic (60°C) temperatures in Class B biosolids. Unlike other studies, this study utilized a scrapie cell assay to determine infectivity and quantity of infectious prions. The best method for extraction was exposing the biosolids to 4 M urea at 80°C for 10 minutes followed by a membrane centrifugation to reduce the concentration of urea. The recovery efficiency of the infectious prions from the biosolids for this method was 17.2%. In the survival study, a 2.43-log(10) reduction in prion infectivity was observed under mesophilic temperatures after 15 days and a 3.41-log(10) reduction after 10 days under thermophilic conditions. The reduction of infectious prions was greater in the biosolids than the control in phosphate buffered saline, suggesting factors other than temperature were also playing a role in the loss of infectivity of the prions in the biosolids.
authors.affiliation: Soil, Water, and Environmental Science Department, University of Arizona, Tucson, Arizona, USA. smiles@email.arizona.edu
authors.forename: Syreeta L
authors.initials: SL
authors.lastname: Miles
authors.forename: Kazue
authors.initials: K
authors.lastname: Takizawa
authors.forename: Charles P
authors.initials: CP
authors.lastname: Gerba
authors.forename: Ian L
authors.initials: IL
authors.lastname: Pepper
mesh_terms: D000818:Animals; D001130:Arizona; D001681:Biological Assay / Q000379:methods; D002417:Cattle; D018929:Cell Culture Techniques / Q000379:methods*; D002478:Cells, Cultured; D008460:Meat; D051379:Mice; D018620:PrPSc Proteins / Q000032:analysis*; D012037:Refuse Disposal; D012608:Scrapie / Q000635:transmission*; D013696:Temperature; D014020:Tissue Extracts
chemical_list: D018620:PrPSc Proteins; D014020:Tissue Extracts